JP3650958B2 - Sand pile construction method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a method for constructing sand piles on soft ground, and in particular, without significantly using a vibro hammer (vibrator), the diameter of the sand piles is greatly increased and stronger than a hollow pipe (casing) for sand pile construction. The present invention relates to a method for constructing a sand pile with low vibration and noise that can be compacted.
[0002]
[Prior art]
When sand piles are created on soft ground on land, it is necessary to pay close attention to vibration and noise generated during sand pile construction when there are people, hospitals, schools, etc. nearby.
[0003]
However, in the conventional sand pile construction method, it is necessary to use a vibro hammer at the time of penetration and withdrawal of the hollow pipe for sand pile construction and at the time of re-penetration for sand pile diameter expansion and compaction. Since we had to work with care so that vibration and noise did not exceed standard values, it was difficult to obtain high-quality compacted sand piles, and the construction period was long and construction costs were high. there were.
[0004]
[Problems to be solved by the invention]
The present invention proposes a method capable of constructing a high-quality compacted sand pile that is greatly expanded in diameter compared with a hollow tube with low vibration and low noise without using a vibro hammer.
[0005]
[Means for Solving the Problems]
Therefore, in the present invention, the sand pile forming hollow pipe is configured to be rotatable forward and backward in its circumferential direction, and a sand discharge pipe bent to one side with respect to the hollow pipe is provided at the lower end of the hollow pipe. A drilling device is used, which is provided in a continuous manner and is provided with a downward-facing cone-shaped molding roller that is rotatably mounted on the outer periphery of the discharge pipe, and a drilling tooth is fixed to one side of the lower end of the roller.
[0006]
This drilling device is known as a drilling jig developed by German Bauer company for on-site piles (Japanese Patent Laid-Open No. 9-112171). This Bauer device does not discharge the excavated soil to the ground, but presses it against the drilled hole wall while compressing it with the molding roller at the lower end, thereby strengthening the hole wall, A hardener such as cement milk is used.
[0007]
However, since this device is not intended for sand pile formation on soft ground, it does not assume the formation of a solid compacted sand pile whose diameter has been expanded as a whole.
[0008]
As an application of such an apparatus, the present invention is intended to form a compacted sand pile that can be greatly expanded in diameter as compared with the diameter of the hollow pipe for sand pile formation as described above.
[0009]
That is, the present invention is configured such that the sand pile building hollow pipe can be rotated forward and backward in the circumferential direction, and a sand discharge pipe bent in one direction with respect to the hollow pipe is communicated with the lower end of the hollow pipe. First, using a drilling device provided with a downward-facing cone-shaped molding roller mounted on the outer periphery of the discharge pipe so as to be freely rotatable and having a drilling tooth fixed to one side of the lower end of the discharge pipe, In the process of penetration to the design depth of the soft ground by the rotation of the above hollow tube, the excavated soil is moved and compacted to the side with a molding roller, and the penetration hole larger than the diameter of the hollow pipe is opened while holding the penetration hole Next, a predetermined amount of sand is introduced into the hollow tube, and the hollow tube is pulled out to a predetermined height while blowing compressed air, whereby the sand in the hollow tube is discharged from the discharge tube and below the discharge tube. Then, it is discharged by filling it in the drilling hole and then penetrating it again to the specified height while rotating the hollow tube The sand pile is taken in with the excavating teeth and rolled sideways and downwards with a forming roller to expand the diameter of the sand pile under construction and compress it to the bottom and side. Then, the hollow tube is pulled out to a predetermined height and filled into the drilling hole while discharging sand, and thereafter the hollow tube is removed while repeating such sand discharging operation, hollow tube drawing and re-penetrating operation. The present invention relates to a sand pile forming method characterized by forming a compacted sand pile expanded to a predetermined diameter by pulling out from a soft ground step by step. Hereinafter, embodiments of the method of the present invention will be described with reference to the drawings.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a lower end portion of a sand pile forming hollow tube 1, which is rotatable forward and backward in the circumferential direction by a drive motor (not shown) installed above. . Reference numeral 2 denotes a sand discharge pipe attached and fixed to the lower end of the hollow pipe 1 so as to communicate with the pipe 1 downward. The discharge pipe 2 has a diameter smaller than that of the hollow pipe 1 and is a shaft of the hollow pipe 1. For example, the sand is introduced into the hollow tube 1 so as to be bent at an angle of about 3 to 15 ° with respect to the core, and the communicating portion 3 with the hollow tube 1 is formed in a funnel shape. 10 flows smoothly into the discharge pipe 2. Reference numeral 4 denotes a downward digging tooth attached to the lower end of the inclined discharge pipe 2, which is attached to the opposite side of the inclined side of the discharge pipe 2 so as to slightly protrude outward from the hollow pipe 1.
[0011]
Reference numeral 5 denotes a downward-facing cone-shaped molding roller that is rotatably supported on the outer periphery of the discharge pipe 2, and the roller 5 bulges from the outer diameter of the hollow pipe 1. Therefore, when the hollow tube 1 rotates about its axis, the roller 5 at the lower end rotates eccentrically with the discharge tube 2 and slips in the soft ground due to its frictional resistance or in the direction opposite to the hollow tube 1. Rotate.
[0012]
Reference numeral 6 denotes a compressed air injection nozzle, which has a plurality of stages (for example, three to four stages) on the side wall of the hollow tube 1 and a plurality of them on the same circumference so that their positions are shifted in relation to the upper and lower stages. The lowermost nozzle 6 is inserted into the funnel-shaped communication portion 3 described above.
[0013]
Thus, the sand pile is constructed as follows by the method of the present invention. First, the hollow tube 1 is rotated forward to penetrate the soft ground 7 to a predetermined depth while turning the excavating teeth 4 at the lower end slightly, and a penetration hole having a larger diameter than the hollow tube 1 is cut (see FIG. 2). ).
[0014]
At the time of drilling by rotating penetration of the hollow tube, the excavated soil by the lower-end excavating teeth 4 is free space 9 between the eccentric molding roller 5 on the upper side and the wall 8 of the lower portion of the hollow tube 1 that has been cut. And simultaneously compressed by the peripheral surface of the molding roller 5 and pressed against the wall of the hole 8.
[0015]
When the hollow tube 1 has penetrated to a predetermined depth, the hollow tube 1 is stopped from rotating and a predetermined amount of sand 10 is thrown into the tube 1. The hollow tube 1 is pulled out to a predetermined height in the ground 7 while blowing compressed air from each nozzle 6, sand is discharged from the lower end of the discharge pipe 2, and a cut hole 8 below the discharge pipe 2 is cut. The inside is filled with discharged sand (see FIG. 3).
[0016]
Next, the hollow tube 1 is returned to the normal rotation while maintaining the pressurized state, and penetrates again to a predetermined height (FIG. 4). Due to this re-penetration, the sand immediately below is crushed and compacted, and at the same time, the sand is spread outward and expanded, and the discharged sand from the lower end is used for the compaction and expansion of the lower diameter, and at the same time as the above-mentioned drilling. The sand discharged by the eccentric rotation of the molding roller 5 is taken in by the excavating teeth and pressed toward the side in the vicinity of the roller 5 in the same manner as the movement of the excavated soil in the above. Compression compaction is performed (see FIG. 4). In this case, the diameter of the sand pile 11 can be adjusted by the rotational operation time of the hollow tube 1 at the same height position and the discharge amount of the sand 10 at the height position.
[0017]
When the sand pile deepest part that has been compacted and expanded to a predetermined diameter in this way is formed, the sand is supplied into the hollow tube 1 and pulled out to a predetermined height while rotating the hollow tube 1 in the reverse direction again. At the same time, the hole 8 that has been cut off is filled while discharging sand, and then the hollow tube 1 is re-penetrated by the same operation as described above (see FIGS. 5 to 6).
[0018]
By pulling out the hollow tube 1 stepwise from the soft ground 7 while repeating such sand discharging operation, pulling the hollow tube 1 halfway through the soft ground 7, re-penetrating operation and forward / reverse rotation operation. Then, the compacted sand pile 11 expanded to a predetermined diameter is created (see FIG. 7).
[0019]
Then, the lower end of the hollow tube 1 reaches the ground surface, and the hole 8 that has been drilled and finally left in the vicinity of the ground surface is completely pulled out to fill the sand in the hollow tube 1 (see FIG. See FIGS.
[0020]
【The invention's effect】
The sand pile construction method of the present invention is as described above, and it is not necessary to use a vibro hammer for penetration, extraction and re-penetration of the hollow pipe for sand pile construction into the soft ground as in the past. Since it is possible to efficiently create a strong compacted sand pile that has been expanded to a predetermined diameter with vibration and low noise, it is optimal for sand pile construction on soft ground on land where people are living nearby.
[0021]
Further, when the excavated soil is pressed to the side, it is possible to form a stronger ground together with the sand pile that is compacted and compacted in the lateral direction.
[0022]
In addition, the amount of bulge on the ground surface is reduced, so that the conventional work for removing the laid soil is not required, leading to reductions in construction costs and the like.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a lower end portion of a hollow tube (casing) used in a sand pile forming method of the present invention.
FIG. 2 is an explanatory diagram showing a process during the creation of a sand pile by the method of the present invention.
FIG. 3 is an explanatory diagram showing a process during the creation of a sand pile by the method of the present invention.
FIG. 4 is an explanatory diagram showing a process during the creation of a sand pile by the method of the present invention.
FIG. 5 is an explanatory diagram showing a process during the creation of a sand pile by the method of the present invention.
FIG. 6 is an explanatory diagram showing a process during the creation of a sand pile by the method of the present invention.
FIG. 7 is an explanatory diagram showing a process during the creation of a sand pile by the method of the present invention.
FIG. 8 is an explanatory diagram showing a process during the creation of a sand pile by the method of the present invention.
[Explanation of symbols]
1-Hollow pipe (casing) for sand pile construction
2-Inclined sand discharge pipe 3-Funnel-shaped communication part 4-Excavation teeth 5-Molding roller 6-Compressed air injection nozzle 7-Soft ground 8-Open hole 9-Free space 10-Input sand 11-Sand pile

Claims (1)

  The sand pile forming hollow pipe is configured to be rotatable forward and backward in the circumferential direction, and a sand discharge pipe bent in one direction with respect to the hollow pipe is connected to the lower end of the hollow pipe. A drilling device provided with a downward-facing cone-shaped molding roller attached to the outer periphery of the discharge pipe so as to be freely rotatable and having a drilling tooth fixed to one side of the lower end of the discharge pipe is used. In the process of penetrating to the design depth of the soft ground by rotation, the excavated soil is moved and compacted to the side by a forming roller, and the penetration hole larger than the diameter of the hollow tube is opened while holding the penetration hole. A predetermined amount of sand is poured into the hollow tube, and the hollow tube is pulled out to a predetermined height while blowing in compressed air, whereby the sand in the hollow tube is discharged from the discharge tube and filled in the cut hole below the discharge tube. Next, the sand that has been discharged by re-penetrating to the predetermined height while rotating the hollow tube is removed. Incorporation, rolling of the molding roller to the side and downward by rolling to the side and the diameter of the sand pile under construction and compression compression to the bottom and side are performed, and then the sand is supplied again into the hollow pipe. The hollow tube is pulled out to a predetermined height and filled into the drilling hole while sand is discharged, and thereafter the hollow tube is softened step by step while repeating such sand discharging operation and drawing and re-penetrating operation of the hollow tube. A sand pile construction method characterized by creating a compacted sand pile expanded to a predetermined diameter by pulling out from the ground.

Images